As shown for example by U.S. Pat. No. 4,675,497, laser cutters for sheet material are known for cutting parts from thin sheet material and wherein the work material is supported on a support surface, a laser beam is projected onto the work material from a projector part located above the work, and the work material supported on the support surface and projector part are moved relative to one another in two coordinate directions to cause the beam to trace and cut a desired two dimensional line on the sheet material defining the periphery of a desired part. When the pieces of sheet material to be cut are of significant size, as for example in the case of working on sheets of cloth from which clothing, upholstery or air-bag parts are to be cut, the relatively moving parts of the cutter become quite massive so that considerable inertias are associated with the drives for moving the projector part and the work material relative to one another in each of the two coordinate directions. The resulting difficulty in accelerating and decelerating the relatively moving parts has in general made it necessary to operate the cutters at relatively slow speeds in order to cut with reasonable accuracy, especially in cases where the parts to be cut from the work material are of complex shapes requiring the beam to be stopped and restarted, or at least slowed, at corner points or other points at which notches, holes, or other small features of intricate nature are to be cut. Such cutters, capable of cutting at reasonably acceptable speed and accuracy, have also been costly to manufacturer.
The object of this invention therefore is to provide a laser cutter and method of the foregoing character which avoids the drawbacks previously flowing from the high inertias of the two dimensional drive system and which allows complex shapes to be cut from the work material at a more desirable combination of speed and accuracy than has heretofore been possible.
A further object is to provide a laser cutter capable of cutting intricate shapes in sheet material with reasonable speed and accuracy and capable of being made at reasonable cost.